A wireless device and method for a multiple carrier system are provided. The wireless device comprises a carrier management unit for determining at least one of a plurality of carriers as a reference carrier for monitoring a control channel and a control channel unit for monitoring the control channel over the reference carrier, wherein the carrier management unit switches the reference carrier to at least one of remaining carriers of the plurality of carriers. Accordingly, control channel traffic can be prevented from concentrating on a particular carrier, and a diversity gain can be achieved.